The present invention relates to a display apparatus to be employed in a television set, a computer periphery display, or the like.
The conventional display apparatus will be described with reference to the accompanying drawings.
FIG. 19 is a perspective view of essential portions of a conventional display apparatus 301, which includes a rear electrode 302, a plurality of linearly elongated heat electrodes 303 which are sources for generating electron beams, an electrode unit 304, and a face plate 306 formed with a fluorescent screen 305.
In the electrode unit 304, a plurality of electron beam control electrodes 307a, 307b, 307c, and 307d are fixedly laminated together by insulating spacers 308a, 308b, and 308c. The spacers 308a, 308b, and 308c are comprised of metallic core members 308aa, 308ba, 308ca and bonding layers 308ac, 308bc, 308cc on both surfaces thereof. The insulating films 308a b, 308b b and 308cb are made of crystalline low melting temperature solder glass, and formed into insulating films by preliminarily sintering and fixing them around core members 308aa, 308ba, and 308ca. The bonding layers 308ac, 308bc, and 308cc are made of amorphous or crystalline low melting temperature soldering glass, and after positioning and laminating the electron beam control electrodes 307a, 307b, and 307c via spacers 308a, 308b, and 308c, the electron beam control electrode 307a, 307b , and 307c are bonded and fixed by blazing, to thereby obtain the electrode unit 304.
The operation of the electrode unit 304 will now be explained.
When a predetermined current is fed to the heat electrodes 303 and predetermined electric potentials are applied to the rear electrode 302, the plurality of electron beam control electrodes 307a, 307b, 307c, 307d and the fluorescent screen 305-, electron beams are directed toward the electron beam control electrode 307a. The electron beam control electrodes 307a, 307b, 307c, and 307d are formed with electron beam passage holes or slits therein, and electron beams are, while passing through these holes or slits, controlled, focused, and deflected by voltages applied to respective electrodes, so that they arrive at the fluorescent screen which has a high voltage applied thereto to generate fluorescent light on the fluorescent screen, to thereby obtain a picture.
However, in the construction of such an electrode unit 304 as referred to above, since the electron beam control electrodes 307a, 307b, 307c, and 307d are laminated and fixed to each other via spacers 308a, 308b, and 308c, there arises deformations in the electron beam control electrodes 307a, 307b, and 307c due to variations in the thickness of the insulating films 308ab, 308bb, and 308cb and variations in the thickness of the bonding layers 308ac, 308bc, and 308cc. Furthermore, it is necessary to heat at 400.degree. to 600.degree. C. for bonding and fixing. Therefore, there occurs oxidization due to the high temperatures and deformations due to the thermal stress in the electron beam control electrodes 307a, 307b, and 307c. Furthermore, because the areas of the insulating films 308ab, 308bb, 308cb, and the bonding layers 308ac, 308bc, 308cc between the electron beam control electrodes 307a , 307b, and 307c are comparatively large, respective electrostatic capacitances between the electron beam control electrodes are large resulting in the problem that the power for driving must be increased.
The present invention aims to solve such problems of the conventional art.